During the latter part of the 19th and early 20th centuries, the company expanded its mining activities, also acquiring shipping firm Stephenson Clarke in 1928.

The remainder of the company diversified, mainly into shipping and engineering, and acquired the ports of Tees and Hartlepool in the 1990s.

[2] In 2005 the company was acquired by infrastructure division of Babcock & Brown,[3] and then sold to Brookfield Asset Management in 2009.

[7] From the 1830s Powell began assembling his own shipping fleet, and also invested £20,000 in the Taff Vale Railway.

[7] Shortly before his death he arranged the merger of his business interests with those of Sir George Elliott, forming the Powell Duffryn Steam Coal Company Ltd in 1863 with a capital of £500,000.

[7] In 1867 the company acquired the Aberaman Estate from iron master Crawshay Bailey, the land of which held much good quality 'steam coal'.

The company started a joint venture in the shipping industry with Stephenson and Clarke in 1920, later acquiring their partners outright by 1928.

The merged company included the Cambrian Wagon Works, adding an engineering arm to the business.

[5] By the 1980s the company was showing good profitability; the Hanson Trust made an unsuccessful takeover attempt in 1984.

[16][17] A bid by Babcock and Brown Infrastructure (BBI) at 150p per share, with total value £337 million was recommended in December 2005.